Method for producing bulky yarn

ABSTRACT

Polypropylene multifilament yarn is continuously jetted from a jet nozzle toward a stuffing member composed of numerous stuffing elements together with super heated steam from the jet nozzle during the relative displacement of the jet nozzle to the stuffing member. The stuffing member is provided with cubical spaces for retaining the multifilament yarn. The multifilament yarn is fixed its deformation by the plastifying action of the super heated steam while being retained in the cubical spaces of the stuffing member, and next the multifilament yarn having crimps is stripped from the stuffing member. The above-mentioned process can be performed as a part of a continuous process composed of drawing and crimping, or of melt spinning, and drawing and crimping. Several types of stuffing members including a cylindrical stuffing member covered by numerous needles or honey-comb like elements, a pair of endless-belt type stuffing members, and a cage type are disclosed.

United States Patent [1 1 Ozawa et a1.

[ Apr. 2, 1.974

[ METHOD FOR PRODUCING BULKY YARN 2 2 Filed: Dec. 10,1968

21 Appl. No.: 782,628

3,251,181 5/1966 Breen et a1. 28/72.12 X 3,457,611 7/1969 Nechvatal etal 28/72.12 X

FOREIGN PATENTS OR APPLICATIONS 651,831 11/1962 Canada 28/72il2 PrimaryExaminer-Robert R. Mackey Attorney, Agent, or FirmRobert E. Burns;Emmanuel J. Lobato [57] ABSTRACT Polypropylene multifilament yarn iscontinuously jetted from a jet nozzle toward a stuffing member composedof numerous stuffing elements together with super heated steam from thejet nozzle during the relative displacement of the jet nozzle to thestuffing member. The stuffing member is provided with cubical spaces forretaining the multifilament yarn. The multifilament yarn is fixed itsdeformation by the plastifying action of the super heated steam whilebeing retained in the cubical spaces of the stuffing member, and nextthe multifilament yarn having crimps is stripped from the stuffingmember. The abovementioned process can be performed as a part of acontinuous process composed of drawing and crimping, or of meltspinning, and drawing and crimping. Several types of tltuffing membersincluding a cylindrical stuffing member covered by numerous needles orhoney-comb like elements, a pair of endless-belt type stuffing members,and a cage type are disclosed.

6 Claims, 11 Drawing Figures PATENTEB APR 2 I974 SHEET 1 0F 4PATENTEBAPR 2:914 3800.374

SHEET 3 OF 4 INVENTOR ATTORNEY PATENTEHAPR 2mm v v 3,800,374

saw u or 4 INVENTOR ATTORNEY 1 METHOD FOR PRODUCING BULKY YARN Thisinvention relates to a method for producing bulky yarn composed ofcrimped polypropylene filaments, and to a novel apparatus for carryingout this process.

In general, polypropylene fiber is provided with higher crystallinitythan other synthetic fibers such as, polyamide fiber and certainradicals such as, thermally active radicals or chemically activeradicals and consequently, it is difficult to produce a bulkypolypropylene yarn having stable crimps where the conventional method oftexturing synthetic yarn is applied.

It is well-known that a superior set of synthetic fiber can be obtainedby crimping of the fiber by heat in a wet condition in comparison withthe conventional methods utilizing dry heat.

Consequently, in the present invention, polypropylene filaments having apreferably high setability are only considered, and an economical andpractical method for treating the material-yarn with a practical speedof processing is disclosed.

The principal object of the present invention is to provide a method andapparatus for producing bulky yarn having remarkable crimp-effects bymeans of fixing the fibrous structure of polypropylene filaments havinglow crystalline structure in a condition of high crystalline structurewhile the polypropylene structure is mechanically crimpedsimultaneously.

Another object of the present invention is to provide a method andapparatus for producing bulky yarn having frequent interlacing ofcomponent filaments and stable crimps arranged in the yarn at random.

Still another object of the present invention is to provide a method andapparatus for producing crimped yarn free from any deformation of thecross'section of the filaments and degradation of filaments by fiber inhigh temperature, by means of heating the circumference of eachindividual filament.

A further object of the present invention is to provide an economicaland practical method and apparatus for producing bulky yarn.

A still further object of the present invention is to provide a methodand apparatus for continuously (simultaneously) operating the drawingprocess with the crimping process after the melt spinning process.

Other objects and features of the invention will more fully appear fromthe following description and the accompanying drawings and will beparticularly pointed out in the claims.

FIG. 1 is a sectional view of an embodiment of the apparatus of thepresent invention,

FIG. 2 is an enlarged sectional view of a portion of the nozzle of theyarn feeding and heating device of FIG. 1,

FIG. 3 is a view of a high bulk multifilament yarn which has been madeinto a bulky configuration composed of crimped filaments according tothe present invention,

FIG. 4 is a schematic view of a portion of a cylindrical barrier memberof the apparatus shown in FIG. 1,

FIG. 5 is a schematic view of a portion of a modified cylindrical memberof the apparatus according to the present invention,

FIGS. 6, 7 and 8 are sectional views of other embodiments of theapparatus of the present invention,

FIG. 9 is a schematic view of the apparatus shown in FIG. 1,

FIG. 10 is a skeleton diagram of a continuous apparatus comprising adrawing device and texturing device in accordance with the presentinvention, and

FIG. 11 is a skeleton diagram of another continuous apparatus comprisingspinning and drawing and texturing devices in accordance with thepresent invention.

Generally, the method for producing bulky yarn of the present inventioncomprises stuffing polypropylene multifilament yarn having a fiberdensity below 0.901 for example, undrawn yarn, yarn produced by drawspinning at a draw ratio in a range between 1.5 and 3.0, or cold-drawnyarn produced by a drawing process at room temperature or a temperaturebelow C, into a stuffing device having numerous hard projectionstogether with a stream of super heated steam, whereby fine irregularcrimps are randomly imparted to the individual filaments and thefilaments are plastified simultaneously. Therefore, the crimps of themultifilament are completely fixed. To attain the objects of the presentinvention, polypropylene multifilament yarn having low crystallinestructure, in other words having a structure of mainly semeti-crystal,is preferably used. The semeti-crystal of the polypropylenemultifilaments is changed to a mono-clinic structure by heat treatmentat high temperature in a wet condition so as to fix the crimps in themultifilament yarn. It is required to heattreat the polypropylenefilaments at a sufficiently high temperature in a wet condition for asufficient time to obtain a stable heat setting of the crimps andconvert the molecular structure of the polypropylene filaments. Toattain the above-mentioned objects, super-heated steam at high pressureis used for carrying the multifilament yarn to the stuffing means via ajet nozzle, whereby the yarn is positively supplied to the stuffingmeans.

The stuffing means of the present invention comprises a movable bodycomposed of a stuffing member having a plurality of projections which donot disturb the stuffing of the material into the stuffing member by thestream of super heated steam. Further, as the filaments on the stuffingmember are conveyed by the movement of the stuffing member for apredetermined distance and time, a sufficient time for stable setting ofthe crimps by super heated steam can be utilized. The stuffing of theyarn into the stuffing member is performed by the stream the superheated steam and, therefore, the individual filaments can be deformed inany direction, whereby, random crimps of the filaments can be obtainedin any direction while the conventional mechanical stuffing operationprovides crimps of filaments in primarily one direction.

In the present invention, the stuffing means is moved during theoperation and a certain resistance to the taking up of the yarn from thestuffing means while moving the stuffing member is inevitable. Theabovementioned resistance causes cutting of filaments, making a fuzzyand poor appearance of the product bulky yarn.

To avoid the above-mentioned drawback of the present method, thefineness of the filaments is preferably chosen in a selected range offineness, that is, the fineness of the individual filaments in a rangebetween 10 denier and 50 denier is preferable so as to attain theobjects of the present invention. If the yarn used is composed ofindividual filaments having a fineness over 50", the result of thestuffing operation is not satisfactory since, development of very roughcrimps occurs.

A shrinkable composite polypropylene multifilament yarn can also be usedto attain the present purpose. In this case, the combined effect of thecrimping by the shrinkable property of the yarn with the abovementionedstuffing operation will produce bulky yarn having excellent bulkinessand stretchability.

Referring to FIG. 1, a polypropylene multifilament yarn l is fed by apair of feed rollers 2a and 2b to ajet nozzle 3, and the yarn l isstuffed into a cylindrical stuffing member a disposed on thecircumferential surface of a cylinder 5 together with super heated steamwhich is supplied to the nozzle 3 by way ofa connecting conduit 4secured to the nozzle 3 as shown by an arrow 4a. The jet nozzle 3 ispositioned in close proximity to the rotating surface of the stuffingmember 5a of the cylinder 5. The circumferential speed of the feedrollers 2a and 2b is constant. In this embodiment, the cylindricalstuffing member 5a is composed of numerous needle-like projectionsdisposed on the circumferential surface of the cylinder 5. Therefore,there are numerous fine cubical spaces in the stuffing member of thecylinder 5. The multifilament yarn I, caught by the cubical spaces ofthe stuffing member 5a, is carried with the rotation of the cylinder 5and finally taken up from the stuffing member 5a by a pair of deliveryrollers 6a and 6b and wound into a package by a conventional windingmeans.

The jet nozzle 3 is composed of a main cylindrical body 7 provided witha jet conduit 7a and a yarn guide member 8 engaged at its forward endwith a rearward portion of the jet conduit 7a. The connecting conduit 4is also connected at its one end with the cylindrical body 7, as shownin FIG. 2. The super heated steam is supplied to the jet conduit 70 froma supply source via the connecting conduit 4. The multifilament yarn 1is sucked into the jet conduit 7a by the suction caused by the superheated steam supplied from thejet conduit 7a in a high pressurecondition, and then blown toward the stuffing member 5a of the cylinder5, whereby the multifilament yarn 1 comes in contact with the superheated steam while being carried from the yarn guide member 8 to thestuffing member 5a. The individual filaments of the yarn 1 areinterlaced with each other by the high pressure of the super heatedsteam and when the yarn l is impinged onto the stuffing member 5a, themultifilament yarn l is stuffed into cubical spaces of the stuffingmember 50 at random, whereby the desired fine crimps of the filamentsare imparted. As the super heated steam blows toward the stuffing member5a, the crimps of the filaments are set.

The shape of the filament crimps obtained by the abovementioned processhas a particular configuration composed of numerous interlaced filamentshaving stable fine crimps developed in random arrangement as shown inFIG. 3. Further it is noticed that the shape of the crimps is a cubicalone. Consequently, the yarn produced by the present method has anexcellent bulkiness and soft handle. The bulkiness of the textile cloth,such as a tufted carpet made of the multifilament yarn of the presentinvention, is so sufficient that a textile cloth having very lightweight effectively be produced.

Referring to FIG. 4, the stuffing member 5a comprises a foundation-cloth10 secured to the cylindrical surface 11 of the cylinder 5 and numerousneedles 9 perpendicularly disposed onto the foundationcloth 10. Theneedles 9 are made of stainless steel. Various densities and sizes ofthe needles 9 can be used in accordance with the requirements for crimpconditioning, that is, when finer crimps are required, a larger densityof needles must be applied.

By our experiment, was noticed that a ratio between the height (1) ofthe needles 9 and a distance (p) between the adjacent needles is veryimportant for attaining our purpose and it is preferable to apply theratio I/p in a range from 3 to 5. When the ratio l/p is below 3, theyarn stuffed into the stuffing member 5a can possibly escape from thestuffing member 5a and when the ratio l/p is over 5, the yarn is stuffedinto the cubical spaces of the stuffing member 5a so tightly that theresistance for stripping the yarn from the stuffing member 5a becomeslarge, whereby breakage of the filaments occurs.

The density of the needles in a range between SOD/square inch and900/square inch is desirably used and the height of the needles within arange of 3 mm to 10 mm is preferably applied to attain the purpose ofthe present invention. Further, the sharper the tip portion of theneedles, the smaller is the force necessary for stripping the crimpedyarns from the stuffing member and, therefore fuzzy crimps of the yarncan be prevented. It is desirable that the setting angle of the needlesto the foundation-cloth is slightly inclined to the foundation-cloth,for example, the angle is to and consequently, a smooth stuffing andstripping operation can be obtained.

It is also beneficial that the circumferential surface of the stuffingmember shown in FIG. 4 be covered by a net-like sheet having a veryrough mesh, whereby the combined crimping action by the cubical spacesof the stuffing member 5a and the net-like sheet is imparted to themultifilament yarn, and fine multi-dimensional crimps of the yarn can beobtained.

When the above-mentioned net-like sheet is disposed internally of thestuffing member 5a with a certain space between the foundation 11, thereverse flow of the jetted air from thefoundation after passing throughthe net-like sheet is interfered with by the sheet and, therefore, it isnecessary to blow the jet stream to the stuffing member 5a in a highpressure condition.

Referring to FIG. 5, another embodiment of the stuffing member iscomposed of numeral stuffing elements having cubical space of honeycomblike cross-section. The member 12 is made of stainless steel having avery thin thickness in a range between 0.1 and 0.2 mm, and the length ofthe maximum side of the honeycomb like shape is in a range between 3 and4 mm. The stuffing action, where the stuffing member shown in FIG. 5 isused, is almost the same as the first embodiment, but the resistance forstripping the crimped yarn from the stuffing member 12 is less than inthe stuffing member 5a shown in FIG. 4, and the breakage of filamentscan be prevented, whereby, a bulky-yarn of very fine filaments can beobtained by this second embodiment without obstacles.

To increase the production rate of the processing together with thedurability of the stuffing member, the jet nozzle 7 is relativelychanged in its transversal position to the cylindrical surface of thestuffing member 50 at slow speed. It is also useful to transverselydisplace the stuffing member 5a instead of the transversal motion of thejet nozzle 7. By the abovementioned traverse motion of the jet nozzle 7,the multifilament yarn is provided with effective crimps.

The production rate of the present method must be substantiallyconsidered from a view point of stability of the crimp or in otherwords, the temperature of the jet stream and the time of themultifilament yarn in the cubical spaces of the stuffing member 5a or12, affects the stability of the crimp. Consequently, it is helpful toraise the temperature of the super heated steam as high as possible toincrease the production rate it is also helpful to heat themultifilament yarn before the present treatment to increase theproduction rate.

It is also possible to increase the production rate by extending thestuffing time of the multifilament yarn in the cubical spaces of thestuffing member 5a or 12, because stable setting of the crimps can beobtained in spite of increased rotation speed of the cylinder 5. Toattain the above-mentioned effective stuffing result, the diameter ofthe cylinder 5 must be sufficiently large in order to establish a largecircumferential area of the stuffing member 5a or the transversal supplyof the multifilament yarn from the jet nozzle 3 must be operated at asufficient frequency of the traverse motion of the nozzle 3 to increasethe capacity of the stuffing member 5a. By the above-mentioned method,the production rate of the present method can be remarkably increased incomparison with the conventional bulky treatment of multifilament yarn.

The super heated steam maintained at a temperature in a range from 120Cto 185C is preferably used for the present method.

The relation between the feed speed (V of the multifilament yarn fromthe jet nozzle 3 and the circumferential speed (V of the stuffing member5a or 12, must be carefully chosen or otherwise the condition of thecrimps changes widely. It is preferable to apply the ratio v lyg lll arange from 5 to 15. Further it is desirable to apply the followfig speed ratiosTddfi'ate the present process satisfactorily, that is, V /V1.1 1.5, V /V 1.0 1.2, where V designates the delivery speed of thecrimped yarnfrom the rotating stuffing member, V designates the windingspeed of the crimped yarn delivered from the delivery rollers 6a and 6b.

In FIG. 6, a modified embodiment of the present invention is shown. Thestuffing member comprises a pair of endless needle clothings 14a and 14bwhich are secured to endless belts 13a and 13b, respectively in such away that the needle clothings 14a and 14b face each other with aslightly engaging condition as shown in FIG. 6. The endless belts 13aand 13b are belted on pairs of rollers 15a and 15b, 15c and 15d,respectively. The rollers 15a, 15b, 15c and 15d rotate in the directionshown by the arrows. A jet nozzle 3 having the same construction isdisposed at a position closely adjacent to a starting position 17 facingboth needle clothings 14a and 14b. A pair of delivery rollers 16a and16b are disposed to a position behind the leaving position 18 of bothneedle clothings 14a and 14b. The needle clothings 14a and 14b areprovided with numerous needles perpendicularly secured to theirfoundation, respectively. The distance between the positions 17 and 18and the engaging condition of the needle clothings 14a and 14b must bechosen carefully, because the needle clothings 14a and 14b at theslightly engaging condition form numerous cubical spaces while movingalong the line between the positions 17 and 18. A multifilament yarnsupplied to the component stuffing member by a super heated steam jetfrom the jet nozzle 3 and stuffed into the cubical spaces formed by theneedle clothings 14a and 14b is carried to the position 18. At theposition 18, the needle clothings 14a and 14b disengage and themultifilament yarn carried by the cubical spaces is freed from theneedle clothings 14a and 14b without obstacles, such as sticking to theneedles. While being carried by the cubical spaces of theneedle-clothings 114a and 14b, three-dimensional crimps are imparted tothe multifilament yarn and the crimped yarn is delivered by the deliveryrollers 16a and 16b. It was noticed that the preferable engaging lengthof the needles is 20 to 30 percent in comparison with the height of theneedles.

As mentioned above, the multifilament yarn fed by the jet nozzle 3 tothe stuffing member is sufficiently stuffed into the cubical spacesformed by the engagement of the needle-clothings 14a and 14b via thesuperheated steam and the individual filaments of the yarn stuffed intothe cubical spaces of the stuffing member are subjected to heattreatment by the super heated steam blown from the jet nozzle 3 whilebeing stuffed into the cubical spaces of the stuffing members, wherebyfine and stable crimps of the filaments are produced. Further, needleclothings 14a and 14b disengage at the position 18, whereby the crimpedmultifilament yarn is smoothly stripped from the cubical stuffing spaceswith very low tension.

Referring to FIG. 7, another embodiment of the stuffing member comprisesa pair of cylindrical stuffing components, a main stuffing member 20 anda small stuffing member 22 disposed in a slight engaging condition. Themain stuffing member 20 is composed of a cylindrical needle-clothingsecured to the cylindrical surface of a cylinder 19 continuouslyrotating in a direction shown by the arrow, while the small stuffingmember 22 is also composed of cylindrical needle-clothing secured to thecylindrical surface of a small cylinder 21 continuously rotating in adirection shown by the arrow. It is preferable to apply, for example,coarse needle-density to the stuffing member having small diameter incomparison with the main stuffing member and to apply a fastercircumferential speed to the component stuffing member having smallerdiameter, for example, 20 percent faster than the circumferential speedof the stuffing member having larger diameter. The engagement of theneedles of the component stuffing cylinders is preferably arranged insuch a condition that the engaging length of the needles is in a rangebetween 30 percent to percent of the height of the needles. The jetnozzle 3 having the same structure as shown in FIG. 1 is closelydisposed to the main stuffing member 20 as shown in FIG. 7. The crimpingaction of this embodiment is operated in same manner as the firstembodiment except for the second stuffing member 22, which takes off thecrimped multifilament yarn from the main stuffing member very smoothly.

Referring to FIG. 8, further embodiment of the present inventioncomprises a cylindrical cage 24 and a jet nozzle 3 directly connected byits outlet 3a with the inlet of the cylindrical cage 24 and a pair ofdelivery rollers 25a and 25b disposed in such a way that the outlet ofthe cylindrical cage 24 closely faces a nip point 25c of the rollers 25aand 25b. The rollers 25a and 25b rotate at high speed, and the jetnozzle 3 is provided with a similar structure as in the first embodimentshown in FIG. 2.

In the above-mentioned embodiment, the multifilament yarn is stuffedinto the cage 24 together with the super heated steam from the jetnozzle 3, and the multifilament yarn is taken up from the cage 24 by thedelivery action of the delivery rollers a and 25b. Fine and randomcrimps are imparted to the multifilament yarn and these crimps of theindividual filaments are set by the super heated steam while themultifilament yarn is passing through the cage 24. It is possible tomaintain the condition of the multifilament yarn in the cage bymaintaining the balanced condition of the feeding speed of themultifilament yarn from the jet nozzle 3 and the circumferential speedof the delivery rollers 25a and 25b. The cage 24 is composed of acombination of fine straight stainless steel rods and needles, and themesh between the rods must be below 1 mm, otherwise it is possible forthe individual filaments to escape from the space between the adjacentrods, and the escape of the filaments causes yarn breakage during theoperation. In the practice of the abovementioned embodiment, it isdesirable to discharge the super heated steam in the cage 24 by means ofan exhaust fan (not shown). By our mill test, the feeding speed of themultifilament yarn from the jet nozzle 3 can be more than 300 m/min. andthe production rate of the present device is remarkably higher than theconventional bulky texturing method. In the above-mentioned high speedsupply of the yarn, the crimped yarn is taken up from the cage 24 by thedelivery rollers 25a and 25b the circumferential speed of which may bein a range between one tenth or one fifth of the feeding speed, withoutany obstacles for the winding operation.

In FIG. 9, a practical device of the first embodiment of the inventionis shown. A polypropylene drawn multifilament yarn 26 is supplied from apackage 27 and fed to a pair of feed rollers 29a and 29b under tensionbelow 0.1 g/den. by way of a tension device 28. Next the yarn 26 issupplied to a jet nozzle 30. The jet nozzle 30 is connected to a steamsupply conduit 31 which is connected to a supply source 32 of the superheated steam. The jet nozzle 30 is closely disposed to a stuffing member36 which is already illustrated in the explanation of the firstembodiment. The multifilament yarn supplied to the jet nozzle 30 isjetted to the rotating stuffing member 36 and stuffed into the cubicalspaces of the rotating stuffing member 36. The multifilament yarn isprovided with fine and random crimps as already illustrated, and thendelivered by a pair of delivery rollers 37a and 37b, to form a package39 of the crimped bulky yarn by the frictional contact with a windingroll 40. The super heated steam jet from thejet nozzle 30 is exhaustedby a drafter 33 and cooling air is blown to the cylindrical surface ofthe stuffing member 36 via a duct 34 as shown in FIG. 9 so as to set thecrimps of the filaments in a short time. In the embodiment shown in FIG.9, a plurality of jet nozzles are mounted on the conduit 31 and a yarnguide 38 is attached for separating the multiple units. The jet nozzle30 is so constructed that when the jet nozzle 30 is turned toward thestuffing member 36 the supply of the super heated steam is commenced,and when the jet nozzle 30 is turned toward the opposite direction, thesupply of the steam is stopped.

As already illustrated in the first embodiment shown in FIG. 1, thedistance between the stuffing member and the outlet of the jet nozzle isa very important factor which affects the quality of the yarn. By ourexperiments, in the case of using a multifilament yarn having athickness in a range between 1,000 denier and 2,000 denier, it ispreferable to choose the above-mentioned distance in a range between 3and 5 mm. and in the case of using yarn having a large thickness, theabovementioned distance must be large, but on the contrary, in the caseof a fine thickness, the distance must be small.

A continuous process composed of a draw process and a crimping processutilizing the device of the pres ent invention is shown in FIG. 10. Anundrawn yarn 42 is supplied from a package 41 and a drawing operation isperformed at a drawing zone between a feed roller 43 and a deliveryroller 45, with a constant draw ratio. In the case of drawing in aheated condition, a heater 44 is used in the drawing process. It is alsopossible to use the heater 44 as a pre-heater when it is required tospeed up the texturing operation. The crimping device of this embodimentis similar to the practical device shown in FIG. 9 and, therefore theillustration of the crimping device is omitted. The advantage of theabove-mentioned continuous process is that there is no unbalancedshrinkage of the drawn yarn at the different positions in the package.

Another continuous process including a melt spinning process is shown inFIG. 11. In this embodiment, filaments 47 melt spun from a spinneret 46are drawn by a drawing device composed of feed rollers 50 and 51 anddelivery rollers 52 and 53 after supplying a spinfinish by an oilingroller 48 and passing a guide roll 49. When it is required to operatethe drawing under heat, a heater, such as a ceramic heater 54, ispreferably used. As the delivery speed of the drawing device directlyconnected with the melt-spinning device is so high, in the case ofacontinuous process, it is desirable to apply the device shown in FIG. 8,which has a sufficient capacity for imparting crimps to themultifilament yarn at a processing speed of more than 300 m/min.

EXAMPLE 1 Polypropylene polymer having an intrinsic viscosity ofiifi'su'r'a "111' tetralin is mixed with an adequate quantity ofstabilizer and extruded through a spinning nozzle at a processingtemperature of 270C so as to acquire an undrawn filament yarn. Theundrawn filament yarn is next fed to a draw machine and is subjected toa drawing operation carried out under processing conditions illustratedin Table 1 so as to acquire a multifilament yarn including filaments andhaving a total thickness of 1850 denier. Next, the multifilament yarnthus acquired is processed through the apparatus shown in FIG. 1 atprocessing conditions shown below.

Temperature of the super heated steam in C.

Pressure in the super heated steam in kg/cm 0.8

Effective diameter of the jet nozzle in mm. 1.2 Height of the stuffingmember in mm. 4.0 Diameter of a stuffing member in mm. 0.2 Number of thestuffing members per in 840 Clearance between the jet nozzle end and thestuffing member ends in mm. 5 Feeding speed of the yarn in meters/min.60 Peripheral speed of the stuffing member ends in meters/min. l0Take-up speed of the yarn in meters/min. 51

9 The functional features of the crimped yarn thus ac quired areillustrated in Table 1 together with those of the undrawn filament yarn.

10 the crimps. It is impossible to provide the false-twist type crimpedyarn with the excellent properties of the crimped yarn of the presentinvention because of the riraria amsaammeiiga ea- TABLE 1 Drawingcondition/Items Drawlng ratio 1n percent...

{Tenacity in gldenieruul.

tion. C d l 'Tenacny 1n g/demer mu amen yam Breaking elongation inpercent..

. Miiifil arn Percent shrinkage 1n bo1l1ng water i Percent crimpelongation Percent crimp Percent crimp recovery Breaking elongation inpercent.

Temperature of the heated plate in C...

The items shown in the table are obtained by the following measurements.

A skein of 20 winds is prepared on a reeler having a peripheral lengthof 1 meter under a constant yarn ten sion, hung over a stainless steelrod of 5 mm. dia. for at least eight hours, subjected to a dry thermaltreatment at 70C for minutes under an atmospheric pressure and left forat least four hours in a standard room condition (C and 65 percent RH).After the aforementioned preparation, the hank is loaded with an initialloading of l mg/denier and the length L of the hank at a moment 1 minuteafter loading was recorded. Next, the hank is loaded by 100 mg/denierand the length L, of the hank at a moment 1 minute after loading isrecorded. 2 minutes after unloading, the hank is again loaded with aninitial loading of 1 mg/denier and the length L of the hank at a moment1 minute after loading is recorded. Then, the values of the items aregiven by the following.

Per cent crimp elongation (L L /L X 100 Per cent crimp (L L /L X 100 Percent crimp recovery (L L /L L X 100 As is understood from the resultsshown in Table 1, employment of the drawing operation of the materialyarn at a temperature lower than 90C assures effective manufacture of acrimped yarn having superior crimping properties to those possessed bythe ordinary yarn drawn at a high temperature and a large drawing ratio.Further, it should be noted that, in case of the yarn drawn at a lowtemperature and a small drawing ratio, the tenacity of the parn isremarkably enhanced with considerable reduction in shrinkage in boilingwater and the drawbacks possessed by the material yarn are completelyeliminated by the application of the drawing opration. Being procidedwith random crimps having various crimp pitches and with excellentbulkiness, the crimped yarn thus manufactured is adapted for use in roomaccessories with elegant appearance and excellent elastic properties.Further, because of the air jet type manufacturing system, the crimpedyarn manufactured is provided with improved interlacing effect of thecrimps of the individual filaments resulting in relatively easytreatment of the yarn throughout the whole process. Thus the crimpedyarn of the present invention completely eliminates such drawbacks ofthe conventional stuffing-box type crimped yarn as a low bulkiness dueto two dimensional crimp configuration or an uncomfortable touch due toa zig-zag configuration of limitation in the fineness of the yarnmanufactured. The below shown degrees of randomness are calculatedconcerning the crimped yarn of the present invention drawn at C and adrawing ratio of 3.20 and a crimped yarn manufactured by theconventional mechanical stuffing-box system and the result is 1.89 forthe former and 5.31 for the latter.

Degree of randomness wherein x, Respective length of the crimps.

7= Average length of the N crimps.

S Standard deviation in the length distribution of the N crimps. Withoutregard to the processing conditions, the calculated degrees ofrandomness of the crimped yarns manufactured on the apparatus shown inFIG. 1 are smaller than 2.80 and this proves the preferable randomnessof the crimps possessed by the crimped yarn of the present invention.

EXAMPLE 2 Polypropylene polymer having an intrinsic viscosity of 2.1measured in tetralin is mixed with an adequate quantity of stabliizerand extruded through a spinning nozzle at 275C so as to acquire anundrawn filament yarflrivooienir' and containing filaments.

After being processed through the drawing apparatus shown in FIG. 10,the drawn filament yarn obtained is successively fed to the apparatusshown in FIG. 1. In the drawing operation, the temperature of the heater44 was maintained at 88C, the yarns are drawn at a drawing ratio of 2.2in the region between the feed roller 43 and the delivery roller 45 andthe delivery speed of the yarn is meters/min. The crimping treatment iscarried out almost in the same manner as in Example 1 with the onlyexception being that the processing temperature is kept at C, theperipheral speed of the stuffing member ends is 24 meters/min. and thetakeup speed is 126 meters/min. Thus, differences in the processingconditions resulted from the relatively high processing speed employedin the present example. The crimped yarn thus acquired is provided withexcellent functional features similar to those of the crimped yarnmanufactured in Example 1. Combination of the crimping operation withthe drawing operation adopted in the present example brought aboutthrough the crimping apparatus shown in FIG. 8 under the followingprocessing conditions.

Temperature of the super heated steam in C. 170

preferably compact interlacing of the yarn crimps de- Pressure of thesuper heated steam in kg/cm 2.3 spite the almost non-twistedconfiguration of the yarn manufactured eliminating unfavourable filamentsepa- Diameter of the jet noule in mm. 1.6 ration or fluff formationwhich are usually the cases Inside diameter of the stufiing cage in mm.3.6 with the conventional air jet type crimping system. Length of thestufiing cage in mm. 45.0 stuffing-box type crimping system orfalse-twist type Diameter of the cage needles in mm. 0.3 crimpingsystem. Such compactly interlaced'configura- Number of the cage needles26 tion of the crimps of the yarn resulted in easy handling Feedingspeed of the yarn in meters/min. 480 of the yarn in the subsequentprocessings. Take-up speed of the yarn in meters/min. 425

As is apparent from the above. the yarn can be pro- EXAMPLE 3 15 cessedthrough the apparatus at an extremely high pro- Polypropylene polymerhaving an intrinsic viscosity cessing speed and the crimped yarnmanufactured is of 2.3 measured in tetralin and mixed with an adequateprovided with a unique bulky configuration character quantity ofstabilizer is extruded through a spinning istic to the crimped yarnsmade by the air jet system. nozzle at 278C so as to acquire an undrawnmultifilament yarn of 1,850 denier and containing 120 filaments. Theundrawn multifilament yarn is next fed to EXAMPLE 5 an apparatus shownin FIG. 10 so as to undergo a Polypropylene polymer having an intrinsicviscosity crimping treatment under the following processing of 2.1measured in tetralin and mixed with adequate conditions. quantity ofstabilizer is extruded through a spinning Temperature of the superheated steam in C 153 nozzle of 275C, passed through the oilingapparatus shown in FIG. 11, subjected successively to a drawing Feedingspeed of the yarn in meters/min. 80 operation at 90C and a drawing ratioof 1.7 and subse- Peripheral speed of the stuffing member ends inmequently fed to a crimping apparatus shown in FIG. 8. ters/min. 14 Theprocessing conditions in this example are similar to Take-up speed ofthe yarn in meters/min. 79 those employed in Example 4 with the onlyexception The processing conditions of the yarn through the being thatthe delivery speed of the yarn from the drawcrimping treatment aresimilar to those employed in ing apparatus is 650 meters/min. Thetemperature of Example 1 and the characteristic features of the thesuper heated steam is 175C and the take-up speed crimped yarn thusobtained are shown in Table 2. is 00 me r /min-fiy r tly feeding the filment yarn TABLE 2 Drawn Undrawn filament yarn filament (Temp: 140C) ltemSample yarn (Ratio: 4.50)

gg yam before cfimping 1523.55.22 i.'ll..';.'.;.".a;;;... 4'25 '33Crin'ip'ed 'y u geancity in g/denier. 2.41 3.87 reakmg elongation 111percent... 132 40 Percent Shrinkage in boiling water {Material yarn 3.56.0 Cnmped yarn 0.] 0.2 Percent crimp elongation 38.5 20.5 Percent crimp263 132 Percent crimp recovery 90.3 86.4

- resulting in the provision of excellent crimp elasticity and that,because of such excellent crimp elasticity of the polypropylene crimpedyarn obtained, the textile products made up of such crimped yarns areprovided with novel and unique handling quality and touch.

EXAMPLE 4 A drawn filament yarn which is drawn at a temperature of C anda drawing ratio of 2.5 is processed to the crimping apparatus in thepresent example, the manufacture of the crimped yarn adapted for use inroom decoration can be carried out with the highest productionefficiency and lowest production cost.

Polypropylene polymer pellets having an intrinsic viscosity of 1.45measured in tetralin and mixed with an adequate quantity of stabilizerare fed to a composite spinning machine, melt extruded independently atextruding temperatures of 255C and 325C, spun via gear pumps through aspinning nozzle having holes at a composite ratio of l l and a spinningtemperature of 245C and subjected to a drawing operation at roomtemperature and a drawing ratio of 4.0 so as to acquire a multifilamentyarn of 1,050 denier containing 60 filaments. The multifilament yarnthus obtained is next fed to a crimping apparatus shown in FIG. 8. Theprocessing conditions are similar to those employed in Example 4 withthe only exception being that the temperature of the super heated steamis 155C and the take-up Speed of the maa i fi im tsrslmimlhe crimpedyarn obtained in this manner can be provided with crimps' developed bythe application of the super heated steam together with random crimpsformed by the crimping apparatus of the present invention. In accordancewith the degree of crimps to be expected, it is also possible to processthe yarn at higher processing speeds by lowering the temperature of thesuper heated steam. The combined effect of the aforementioned two typesof crimps enables production of textile products having a wide range ofutilization.

EXAM LE] A polypropylene filament yarn (1,850 denier X 120 filaments)which is drawn at 90C and a drawing ratio of 3.20 in Example 1 isprocessed through the crimping apparatus shown in FIG. 9. In this case,the crimping apparatus is provided with a curved heated plate having asurface curvature of 3,000 mm. and an effective length of 60 cm. anddisposed in between the feed rollers 29a, 29b and the jet nozzle 30. Theyarn is heated at 142C while passing over the heated plate prior tobeing fed to the nozzle. The feeding speed of the yarn is 120 meter/min,the peripheral speed of the stuffing member is 20 meters/min. and thetake-up speed is of 103 meters/min.

TABLE 3 As is apparent from the results shown in the table, despite therelatively smaller crimping property than that obtained in the case ofthe cylinder 36, the crimped yarn manufactured on the apparatus of thepresent example is provided with enhanced tenacity and less formation offluffs due to relatively easy removal of the yarn from the surface ofthe drum of this type.

EXAM P 152.

An apparatus shown in FIG. 7 is accompanied with a small cylinder 21rotating in a meshing condition with the main cylinder 29 and apolypropylene multifilament yarn drawn at 90C and a drawing ratio of3.20 in Example 1 is processed through the apparatus under the followingprocessing conditions.

Diameter of the main cylinder in cm. 70 Diameter of the small cylinderin cm. 15 Peripheral speed of the main cylinder in meters/min.

10 Peripheral speed of the small cylinder in meters/min.

13 Although the resulting functional properties of the yarn manufacturedby the apparatus of the present example is essentially similar to thosemanufactured by the apparatus shown in FIG. 9, the processability of theyarn is outstandingly different. In the case of the apparatus shown inFIG. 9, fluctuation in the removal of the filaments fronilhe surface ofthe cylinder is due to the Crimped yarn Breaking Percent Percent PercentTenacity in elongation crimp Percent crimp shrinkage by g/denier inpercent elongation crimp recovery treatment Feeding speed of the yarn 603.17 64 37.0 25.3 87.5 13.5 in meters/min. 120 3.20 62 38.5 25.8 86.16.1

As is apparent from the results in the table, it is possible to reducethe degree of shrinkage by treatment using the application ofpreheating.

EXAMP E 8 A drum provided with a stuffing member composed of numerousstuffing elements having cubical spaces shown in FIG. 5 is substitutedfor the cylinder 36 of the apparatus shown in FIG. 9. The height of eachstuffing element is 5 mm. and a sidelength of it is 2 mm. Apolypropylene multifilament yarn 1,850 denier X 120 filaments) which isdrawn at 90C and a drawing ratio of 3.20 in Example 1 was processedthrough the aforementioned apparatus under the following processingconditions.

Temperature of the super heated steam in C. 155

Pressure of the super heated steam in kg/cm 0.9

Diameter of the jet nozzle in mm. 1.2 Clearance between the nozzle andthe stuffing box in Feeding speed of the yarn in meters/min. 72Peripheral speed of the stuffing member in meters/- min. l3 Take-upspeed in meters/min. 54 The functional properties of the yarn thusobtained are illustrated in the following table.

Tenacity Breaking Per cent Per Per cent in elongation crimp cent crimpg/dcnier in elongation crimp recovery 3.25 67 34.4 23.9 88.5

difference in the shrinkage of the individual filaments which causesbreakage of the stuffing members. However, by employing the smallcylinder, fluctuation in the removal of the filaments is effectivelyeliminated and the breakage of the stuffing members was effectivelyprevented.

EX MPLE, .9

A polypropylene multifilament yarn drawn at C and a drawing ratio of3.20 in Example 1 is processed through the crimping apparatus shown inFIG. 6 under the following processing conditions.

Temperature of the super heated steam in C. 158

Pressure of the super heated steam in kg/cm 0.95

Tenacity Breaking Per cent Per Per cent in elongation crimp cent crimpg/denicr in elongation crimp eggvery 3,19 66 39.4 27.8 87.3

The crimped yarn of the present example is provided with excellentcrimps due to the combined effect of the ejection by the super heatedsteam with the production of crimps due to the meshing of a pair offacing stuffing member belts. Easy separation of filaments from thesurface of the stuffing members results in provision of enhancedstrength of the crimped yarn obtained. troubles resulting in the case ofthe apparatus shown in FIG. 9 are completely eliminated.

EXAM'PisE 11 An undrawn multifilament yarn (1,850 denier X 120filaments) obtained in Example 1 is fed to a drawing apparatus shown inFIG. 10 and, subsequently and successively, processed through thecrimping apparatus shown in FIG. 1 under the following processingconditions. In this case, the stuffing member is of a bi-layerconstruction having a space intervening between the stuffing member andthe base fabric.

Height of the stuffing members in mm. (Above the base fabric) Number ofthe stuffing members per in 520 Density of the needles per inch.

Position of the needles above the base fabric in mm.

3 Temperature of the super heated steam in C. 158

Feeding speed of the yarn in meters/min. 90

Peripheral speed of the stuffing member in meters/- min. l4

Take-up speed in meters/min. 88

In the present case, with individual filaments being satisfactorilypressed into production members, effective stuffing of crimps upon theindividual filaments is assured without any unfavourable reflection ofthe fluid ejected from the jet nozzle.

While the invention has been described in conjunction with certainembodiments thereofit is to be understood that various modifications andchanges may be made without departing from the spirit and scope of thepresent invention.

What is claimed is:

l. A method for manufacturing bulky yarn composed of a plurality ofcrimped polypropylene filaments comprising, jetting polypropylenemultifilament yarn together with super heated steam into numerousfiberreceptive spaces defined by numerous pin-like protuberances plantedupon a surface member, stuffing said multifilament yarn into saidfiber-receptive spaces continuously by an ejecting force of said superheated steam, simultaneously plastifying said multifilament yarn whilemoving said surface member in a mutually relative condition with saidyarn and without said steam flowing through said surface member,retaining said multifilament yarn temporarily in said fiber-receptivespaces and simultaneously fixing crimp deformations of individualfilaments effected by said stuffing action while being carried by saidfiber-receptive spaces, subsequently stripping said multifilament yarnfrom said fiber-receptive spaces, whereby random and stable threedimensional crimps are imparted to said individual polypropylenefilaments of said yarn.

2. A method for manufacturing bulky yarn according to claim 1, whereinsaid jetting of said polypropylene multifilament yarn together with saidsuper heated steam is along a path transverse to the path of travel ofsaid moving surface member and adjacent and above said fiber-receptivespaces.

3. A method for manufacturing bulky yarn composed of a plurality ofcrimped polypropylene filaments in a spinning process including adrawing and texturing operation, comprising jetting polypropylenemultifila- I ment yarn delivered from a drawing operation together withsuper heated steam into a plurality of numerous fiber-receptive spacesdefined by numerous pin-like protuberances planted upon a surfacemember, stuffing said multifilament yarn into said fiber-receptivespaces continuously by an ejecting force of said super heated steamwithout said steam flowing through said surface member, simultaneouslyplastifying said multifilament yarn, while moving said fiber-receptivespaces in a mutually relative condition with said yarn, retaining saidmulti-filament yarn temporarily in said fiber-receptive spaces andsimultaneously fixing crimp deformations of individual filaments createdby said stuffing action, while being carried by said fiber-receptivespaces, subsequently stripping said multifilament yarn from saidfiber-receptive spaces, whereby fine and random and stable threedimensional crimps are imparted to said individual polypropylenefilaments of said yarn.

4. A method of manufacturing bulky yarn comprising, impinging on asubstantially fluid-impervious, travelling, continuous, surface amultifilament, thermoplastic yarn in a plasticized condition, andpropelled longitudinally along a path onto said surface at a speedgreater than the speed of travel of said surface, while impinging theyarn on said surface crimping said yarn and retaining the multifilamentyarn impinged laterally in laterally-pervious cubical spaces defined byspaced, fixed rigid pins on said surface and distributing longitudinallysaid yarn in said cubical spaces, setting the plasticized yarn on saidtravelling surface, and removing the set yarn as crimped yarn from saidsurface and cubical spaces.

5. A method of manufacturing bulky yarn comprising, propellinglongitudinally along a given path multifilament yarn in a softenedcondition, impinging the softened yarn on a substantiallyfluid-impervious surface travelling relative to said path along a patheffective to develop back pressure on yarn impinged on said surface,before impinging the multifilament yarn on said surface softening saidmultifilament yarn, while impinging the yarn on said surface crimpingsaid yarn and retaining the multifilament yarn impinged on said surfacewith rigid pins upstanding on said surface and distributed thereon in aspaced condition defining fiber-receiving spaces laterally-pervious tofluid for crimping and retaining the impinged yarn laterally at pointsdisposed longitudinally of said yarn, setting the yarn while retained onsaid travelling surface, and removing the yarn from said surface aftersetting as crimped yarn.

6. A method of manufacturing bulky yarn comprising, propellinglongitudinally along a path multifilament, thermoplastic yarn in aplasticized condition, impinging the plasticized yarn on a substantiallyfluidimpervious surface travelling relative to said path substantiallynormal thereto and at a speed less than the speed of longitudinal travelof said yarn being propelled, while impinging the yarn on said surfacecrimping and retaining laterally the yarn at spaced, rigid fixed pinsdistributed longitudinally of the yarn impinged on said surface, settingthe yarn on said surface, and removing the set yam from said surface ascrimped yarn.

1. A method for manufacturing bulky yarn composed of a plurality ofcrimped polypropylene filaments comprising, jetting polypropylenemultifilament yarn together with super heated steam into numerousfiber-receptive spaces defined by numerous pin-like protuberancesplanted upon a surface member, stuffing said multifilament yarn intosaid fiber-receptive spaces continuously by an ejecting force of saidsuper heated steam, simultaneously plastifying said multifilament yarnwhile moving said surface member in a mutually relative condition withsaid yarn and without said steam flowing through said surface member,retaining said multifilament yarn temporarily in said fiber-receptivespaces and simultaneously fixing crimp deformations of individualfilaments effected by said stuffing action while being carried by saidfiber-receptive spaces, subsequently stripping said multifilament yarnfrom said fiber-receptive spaces, whereby random and stable threedimensional crimps are imparted to said individual polypropylenefilaments of said yarn.
 2. A method for manufacturing bulky yarnaccording to claim 1, wherein said jetting of said polypropylenemultifilament yarn together with said super heated steam is along a pathtransverse to the path of travel of said moving surface member andadjacent and above said fiber-receptive spaces.
 3. A method formanufacturing bulky yarn composed of a plurality of crimpedpolypropylene filaments in a spinning process including a drawing andtexturing operation, comprising jetting polypropylene multifilament yarndelivered from a drawing operation together with super heated steam intoa plurality of numerous fiber-receptive spaces defined by numerouspin-like protuberances planted upon a surface member, stuffing saidmultifilament yarn into said fiber-receptive spaces continuously by anejecting force of said super heated steam without said steam flowingthrough said surface member, simultaneously plastifying saidmultifilament yarn, while moving said fiber-receptive spaces in amutually relative condition with said yarn, retaining saidmulti-filament yarn temporarily in said fiber-receptive spaces andsimultaneously fixing crimp deformations of individual filaments createdby said stuffing action, while being carried by said fiber-receptivespaces, subsequently stripping said multifilament yarn from saidfiber-receptive spaces, whereby fine and random and stable threedimensional crimps are imparted to said individual polypropylenefilaments of said yarn.
 4. A method of manufacturing bulky yarncomprising, impinging on a substantially fluid-impervious, travelling,continuous, surface a multifilament, thermoplastic yarn in a plasticizedcondition, and propelled longitudinally along a path onto said surfaceat a speed greater than the speed of travel of said surface, whileimpinging the yarn on said surface crimping said yarn and retaining themultifilament yarn impinged laterally in laterally-pervious cubicalspaces defined by spaceD, fixed rigid pins on said surface anddistributing longitudinally said yarn in said cubical spaces, settingthe plasticized yarn on said travelling surface, and removing the setyarn as crimped yarn from said surface and cubical spaces.
 5. A methodof manufacturing bulky yarn comprising, propelling longitudinally alonga given path multifilament yarn in a softened condition, impinging thesoftened yarn on a substantially fluid-impervious surface travellingrelative to said path along a path effective to develop back pressure onyarn impinged on said surface, before impinging the multifilament yarnon said surface softening said multifilament yarn, while impinging theyarn on said surface crimping said yarn and retaining the multifilamentyarn impinged on said surface with rigid pins upstanding on said surfaceand distributed thereon in a spaced condition defining fiber-receivingspaces laterally-pervious to fluid for crimping and retaining theimpinged yarn laterally at points disposed longitudinally of said yarn,setting the yarn while retained on said travelling surface, and removingthe yarn from said surface after setting as crimped yarn.
 6. A method ofmanufacturing bulky yarn comprising, propelling longitudinally along apath multifilament, thermoplastic yarn in a plasticized condition,impinging the plasticized yarn on a substantially fluid-impervioussurface travelling relative to said path substantially normal theretoand at a speed less than the speed of longitudinal travel of said yarnbeing propelled, while impinging the yarn on said surface crimping andretaining laterally the yarn at spaced, rigid fixed pins distributedlongitudinally of the yarn impinged on said surface, setting the yarn onsaid surface, and removing the set yarn from said surface as crimpedyarn.